Study on the Use of Visual Evoked Potentials for Early Diagnosis of Subclinical Visual System Impairment
| Project/Area Number |
60570369
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurology
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| Research Institution | IWATE MEDICAL UNIVERSITY |
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Principal Investigator |
KUROIWA Yoshiyuki Faculty of Medicine, Iwate Medical University, 医学部, 助教授 (40135249)
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| Co-Investigator(Kenkyū-buntansha) |
MADARAME Hitoshi Faculty of Medicine, Iwate Medical University, 医学部, 助手 (70165736)
HIROI Satoru Faculty of Medicine, Iwate Medical University, 医学部, 助手 (70165215)
NOMURA Tsuyoshi Faculty of Medicine, Iwate Medical University, 医学部, 助手 (30164734)
OHTAKE Toshiyuki Faculty of Medicine, Iwate Medical University, 医学部, 助手 (30160526)
TOHGI Hideo Faculty of Medicine, Iwate Medical University, 医学部, 教授 (90155490)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Visual Evoked Potentials / Pattern Reversal / Multiple Sclerosis / 視神経障害 / ミオクローヌス / 大脳皮質 / ブロードマン17野 / 視覚連合野 |
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| Research Abstract |
A new protocol of continuous monocular pattern reversal stimulation for 30 min was applied to 49 patients with suspected optic nerve pathology and 28 normal adults. A peak latency of P100 in each eye was monitored for 30 min. In normal controls, p100 latency remained normal (below 118 msce) for 30 min. Results in the patient group were divided into three categories; 1) Normal, 2) Type 1 abnormality, and 3) Type 2 abnormality. Only when P100 latency remained normal (below 118 msec) for 30 min, the result was regarded as "normal". When P100 latency was initially normal and at least one of subsequent responses was delayed (longer than 118 msec) or absent, the result was called "type 1 abnormality". When an initial response was already delayed or absent, the result was called "type 2 abnormality". In a conventional method of pattern reversal stimulation, only cases of type 2 abnormality are detected. Our results revealed that this new protocol increases capability of detecting optic nerve pathology. The fraction corresponding to the improved detection rate seemed to be represented by eyes with type 1 abnormality. By using this new testing method, the detection of subclinical lesions of the optic nerve rise from 29 % to 48 %, compared to that of the conventional method which is measurement of one or two evoked potentials obtained by 100-150 summations. In 22 patients with multiple sclerosis, 21 patients (96%) showed either type 1 or type 2 abnormality. In 12 patients with multiple sclerosis without abnormality on ophthalmologic examination, 9 cases (75 %) showed either type 1 or type 2 abnormality. Our new protocol of continuous stimulation for 30 min is very useful for detecting subclinical optic nerve lesions.
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Report
(1 results)
Research Products
(13 results)
